The present invention relates to an improved wiper seal and seal carrier assembly designed for use in sealing the high pressure fluid ends of a reciprocating plunger pump utilized for pumping cement slurries, fracturing slurries, acids and the like for the completion and stimulation of wells in the oil and gas industry.
During the completion and/or stimulation of an oil or gas well, fluids such as cement slurries, fracturing slurries, acids and the like are pumped under pressure into the well. Very high pressures on the order of many thousands of pounds per square inch are typically involved in these pumping operations. Additionally, the fluids are often very abrasive because they carry large quantities of solid particles therein.
This pumping operation is typically achieved by large positive displacement reciprocating plunger-type pumps.
A very difficult sealing problem is encountered at the high pressure fluid end of these pumps, where the abrasive fluid must be prevented from leaking between the reciprocating plunger and the cylinder within which it reciprocates.
Typically, the seal between the reciprocating plunger and the cylinder comprises a packing arrangement including a plurality of V-shaped packing rings constructed of cloth and binder, with various male and female adapters at the forward and rearward ends of those packing sets. A longitudinal compressing is applied to the packing set by an adjusting ring.
Problems encountered in the use of such packing include the deterioration of the V-shaped cloth and binder packing rings due to the hydraulic load from the high pressure fluid end of the pump. A second problem typically encountered is extrusion of the V-shaped cloth and binder packing rings between the small annular clearances present between a female adapter supporting the rearward end of the packing rings and the pump plunger and pump cylinder.
The prior art has included the use of header rings for providing a primary seal between the plunger and cylinder.
The prior art has also included various anti-extrusion devices for preventing extrusion of the packing rings when subjected to high pressures.
The prior art seal carrier has comprised an annular cylindrical sleeve which is used to compress the prior art seal assembly within the fluid end housing of the reciprocating pump to cause the seal assembly to sealingly engage the plunger of the pump.